Serum Amyloid A in Stable COPD Patients is Associated with the Frequent Exacerbator Phenotype.

Abstract

Background:

We sought to determine whether circulating inflammatory biomarkers were associated with the frequent exacerbator phenotype in stable COPD patients ie, those with two or more exacerbations in the previous year.

Methods:

Eighty-eight stable, severe, COPD patients (4 females) were assessed for exacerbation frequency, pulmonary function, fraction of expired nitric oxide (FENO); inflammatory variables were measured in venous blood. Logistic regression assessed associations between the frequent exacerbator phenotype and systemic inflammation.

Results:

Compared with infrequent exacerbators, frequent exacerbators (n=10; 11.4%) had greater serum concentration (median (25th-75th quartile)) of serum amyloid A (SAA; 134 (84-178) vs 71 (38-116) ng/mL; P=0.024), surfactant protein D (SP-D; 15.6 (9.0-19.3) vs 8.5 (3.6-14.9) ng/mL; P=0.049) and interleukin-4 (IL-4; 0.12 (0.08-1.44) vs 0.03 (0.01-0.10) pg/mL; P=0.001). SAA, SP-D and IL-4 were not significantly correlated with FEV1%predicted or FVC %predicted. After adjusting for sex, age, BMI, FEV1/FVC and smoking pack-years, only SAA remained independently associated with the frequent exacerbator phenotype (OR 1.49[1.09-2.04]; P=0.012). The odds of being a frequent exacerbator was 18-times greater in the highest SAA quartile (≥124.1 ng/mL) than the lowest SAA quartile (≤44.1 ng/mL) (OR 18.34[1.30-258.81]; P=0.031), and there was a significant positive trend of increasing OR with increasing SAA quartile (P=0.008). For SAA, the area under the receiver operating characteristic curve was 0.721 for identification of frequent exacerbators; an SAA cut-off of 87.0 ng/mL yielded an 80% sensitivity and 61.5% specificity.

Conclusion:

In stable COPD patients, SAA was independently associated with the frequent exacerbator phenotype, suggesting that SAA may be a useful serum biomarker to inform progression or management in COPD.

• Authors: Dongxing Zhao, Asghar Abbasi, Harry B Rossiter, Xiaofen Su, Heng Liu, Yuhong Pi, Li Sang, Weiyong Zhong, Qifeng Yang, Xiongtian Guo, Yanyan Zhou, Tianyang Li, Richard Casaburi, Nuofu Zhang
• Journal: International journal of chronic obstructive pulmonary disease (Int J Chron Obstruct Pulmon Dis) Vol. 15 Pg. 2379-2388 ( 2020) ISSN: 1178-2005 [Electronic] New Zealand
• PMID: 33061355 (Publication Type: Journal Article)
• Copyright: © 2020 Zhao et al.

Chemical References

• Serum Amyloid A Protein

Topics

• Disease Progression
• Female
• Humans
• Infant
• Lung
• Phenotype
• Pulmonary Disease, Chronic Obstructive (diagnosis)
• Serum Amyloid A Protein